The journal Food and Chemical Toxicology decided to retract the published study on rat tumors because of questionable methodology. It realized that the study did not have ample sample size for it to be conclusive.
Elsevier, the publisher of the journal, had formally issued its statement about the retraction of the paper "Long term toxicity of a Roundup herbicide and a Roundup-tolerant genetically modified maize."
The study was published in the journal's September 19 issue. It created a controversy that was big news at the time which showed images of tumor-stricken rats caused by ingestion of Monsanto's genetically modified maize.
The experiment was conducted on 200 albino Sprague-Dawley rats, which were separated into 10-member groups. Some were provided with genetically modified (GM) corn diets, with or without Roundup weed killer while others were provided with Roundup in water. Control group consisted of 20 rats.
The findings showed that those females under the GM diet group were 2-3 times more likely to end up dead compared to those in the control group. Whether or not they had Roundup weed killers did not change the negative effects it had to their health. From those who ate the Monsanto GM corn, 50 percent of the males and 70 percent of the females had untimely deaths compared to those not eating the corn that only had 30 percent of males and 20 percent females.
Maurice Moloney, Director and Chief Executive of Rothamsted Research, commented to CBS News, "The most evocative part of the paper is those pictures of tumorigenesis. If there was a control that ended up showing similar kinds of tumorigenesis then a picture of that rat should be shown as well, just so we can see if there are any qualitative differences between them."
Because of a lot of letters commenting that Sprague-Dawley rats are prone to tumors and that a 20-member sample group is not enough as control group, the Editor in Chief reviewed the contentions right after publication and asked the lead study author Gilles Eric Séralini to give the raw data gathered from the experiment.
After an in-depth analysis of the data provided by the researchers, Elsevier concluded that there was neither misrepresentation nor fraud involved. However, the sample size of the control group is not ample enough to come up with credible conclusions about heightened tumor incidence and mortality.
"This retraction comes after a thorough and time-consuming analysis of the published article and the data it reports, along with an investigation into the peer-review behind the article. Ultimately, the results presented (while not incorrect) are inconclusive, and do not reach the threshold of publication for Food and Chemical Toxicology," said Elsevier in its press release.
